This invention relates to apparatus for detecting and marking and/or flagging underground utility lines such as electrical power, gas, cable tv and telephone lines.
Location and marking of underground utility lines is important in order to avoid accidental disruption of utility services and destruction of utility lines during subsequent earth moving activities. Location is typically done with a detector responsive to metallic components of the utility line, utilizing electromagnetic energy, for example. The line is then flagged and/or marked above ground level by placement of a series of spaced flags and/or applying a bright paint stripe on the ground and/or grass. Placing of such flags by inserting the flag stem into the ground can be tedious and time consuming, as is known. The flags are either manually inserted into the ground or by use of a tool. Either way, the process is tiring to the workman. The same is true for paint striping the ground.
Efforts have been made to lessen the difficulty and tedium of flag insertion by bending the bottom of each flag staff at an angle and pounding it into the ground with a sleeve-type outer pipe movable on an inner rod, comparable to a typical fence post driver, as in U.S. Pat. No. 5,671,814. This still is tedious and leaves much to be desired, however.